ds store wrote:
What makes a computer fast is: (in order of importance)
1: CPU
2: RAM amount (the more the better)
3: BUS speed
4: GPU performance
(4.5 Network speed)
5: Storage speed.
Remember, once the data is off the storage and into RAM, it's really not needed much anymore after that.
Yes there is the swap file, but if you have enough RAM, then this is minimalized.
This isn't entirely accurate. There's a reason why people's perceptions of speed when they move from a traditional hard drive to an SSD are so pronounced, and why old computers with an SSD suddenly feel faster than a brand new machine with a traditional drive.
That reason is that ALL data has to come from the hard drive before it can get into RAM.
It doesn't matter how fast your CPU is, or how much RAM you have, you have to fill the RAM with data, and that data is coming from what is quickly becoming the slowest component in your computer. The hard drive has been the biggest bottleneck in computers for a long time, but it's been the most difficult to resolve because people were more willing to pay for more storage rather than a faster drive. We also reached the limit for disk speed a long time ago, and pricewise, it wasn't worth the trade off.
Now, flash memory is cheap enough to massive banks of it make for a easy way to boost performance. Yes, once you have your data in RAM, the hard drive is less important. But honestly, if you have less than 16GB of RAM, you're going to be hitting the hard drive to load a program more often than you might think. Particularly in OSX Lion, where Apple tries to keep your RAM full as often as possible.
When you go to find data, and it isn't in RAM, and the RAM is full, the computer writes out the contents of the RAM back to the hard drive (called a "page out", using the swap file you mentioned), then fills the RAM back up with the data you request from the hard drive. Yes, paging is improved dramatically when you have an SSD, but notice that you're hitting the hard drive TWICE ... once to write the data to the hard drive, and again to read new data. These are two different operations, both of which are improved with an SSD. But you're reading from the hard drive far more often than you're writing to it, it most cases, and that has nothing to do with the swap file. The only time a swap file is used is if the RAM is all full and active, and the more RAM you have, the more this is avoided. (OS X is pretty good about RAM usage, though.)
With that out of the way, you also listed "network speed" which is a misnomer. Network speed is important if you're transferring big files between computers on the same network, yes. I suspect for home users, or even in a work environment, that this is rare. Most computers and network switches are at least 100Mbit, and this is fine for most scenarios. The speed of your broadband connection is far more important, and in most cases, you're not even going to saturate a 100Mbit connection because the speed you get from your internet provider is going to be far slower. Should you pay for Gigabit switches and network connections when your broadband speed is only 20Mbit? Depends on whether or not you stream data from another machine in your house on a regular basis. If you're on a wireless network, even that is irrelevant.
GPU performance for everyday tasks reached "good enough" a long time ago. That said, if you do any work in 3D, or use programs that can use a GPU to accellerate functions, this is far more important. Of course, for gamers, this is a big deal. Choices are pretty limited in the Mac realm, but if you can get a discrete graphics solution, opt for that.
If I were going to reorder your list, I'd say it would be more like this ...
1. CPU Technology (which coincides closely with bus speed, buy the fastest, most up to date CPU you can afford, because in a Mac these are not upgradable)
2. Hard Drive speed (go with SSD if you can afford it)
3. RAM quantity (easily upgradable aftermarket, so get the minimum you can and upgrade after to the max the machine can hold)
4. GPU Performance (not easily upgradable aftermarket [except in a Mac Pro], get the best you can afford)
5. Broadband speed
6. Network speed